1. Field of the Invention
The present invention relates to a method of making a drill-shaped cutting tool and thread rolling dies for the same. The drill-shaped cutting tool includes a drill and a self-drilling screw. This tool can make a cylindrical hole or the like on a workpiece by means of rotation thereof.
2. Description of the Background Art
Today, many drills are made by various methods. For instance, striking one of a pair of dies against another may permit the tip of many self-drilling screws to be fabricated into the drill shape.
Nevertheless, in order to perform the foregoing grinding process of the material, various types of processes are needed. Although the process for machining the tip of the screw into the drill-shape by means of striking a die against another may suffice, the fabrication of the threaded part needs another simplified process.